The present invention relates to a continuous riveting machine for fastening blind rivets and, more particularly, it relates to a continuous riveting machine enabling torn core rivet stems to be stored in a torn stem-recovering chamber installed in the riveting machine and enabling each of the partially deformed continuous rivet holders to be discharged.
Up to the present, conventional single rivet-loading riveters were constructed so that a blind rivet was loaded into the under portion of the nose piece of the riveter one by one in every riveting operation, and the torn core rivet stems of each blind rivet were discharged from the above portion of the riveter, as disclosed in prior art laid open publication as Japan Patent Application No. Showa 61 (1986)-78526.
However, in this riveter, because the blind rivet must be inserted for every riveting operation, the riveter was cumbersome to operate and the discharged torn core rivet stems were dispersed all around the working place.
In order to solve the above-mentioned disadvantages, the applicants of the present invention invented the improved continuous riveting machine enabling continuous loading of the blind rivets, preventing the dispersion of torn core rivet stems by discharging them outward together with a rivet-holding belt. This improved continuous riveting machine is disclosed in Japan Patent Application No. Heisei 3 (1991)-152150, and as shown in FIG. 14 to FIG. 23, is comprised of a main body section A, a drive section B and a rivet supply section C.
By combining FIG. 14 with FIG. 15, the improved continuous riveting machine with an operating lever released is displayed as a whole.
By combining FIG. 16 with FIG. 18 or FIG. 17 with FIG. 18, the improved continuous riveting machine with the operating lever gripped is shown as a whole. While the air piston 2 is in the far most advanced position as shown in FIG. 18, each position of the miscellaneous pistons located in the main body section A and the position of the blind rivet are transferred from the state shown in FIG. 16 to that shown in FIG. 17.
The drive section B is composed of a small diametral hydraulic cylinder 12 and a large diametral air cylinder 1 connected to the hydraulic cylinder 12. This hydraulic cylinder 12 is branched sidewise and a little upwardly oblique from the main body section A, and is integrated in one piece with a pneumatic and hydraulic cylinder 5. A piston rod 3 integrated in one piece with a piston 2 is inserted in the air cylinder 1 and slidably inserted in the hydraulic chamber 12a so as to be servable as a piston of the hydraulic cylinder 12.
In the under portion of the air cylinder 1, a shaft hole 41 is shaped and connected to an air exiting port 40 located on the under portion of the air cylinder 1, and a valve chamber 44 is shaped at the rear end of the shaft hole 41. Both enlarged portions of the shaft hole 41 are connected to the air cylinder 1 through connecting paths 42 and 43. Also in the shaft hole 41, a valve shaft 6 having a valve 8 for closing the path 43 at the rear end thereof, and a plug 70 for closing the shaft hole 41 at the front end thereof, are slidably inserted. The valve shaft 6 is usually energized to move forwardly by a spring 25.
A trigger lever 9 and a valve cam 10 are pivotally supported by spring pins 45 and 46 biasing them to rotate clockwise, and the operating lever 9 and the valve cam 10 are connected together with a connecting rod 11 by spring pins 47, 48 pivotally placed on the above portion of the lever 9 and the valve cam 10. Further, the lower tip of the valve cam 10 contacts with the front face of the plug 70.
In the main body section A, a cylindrical rivet nose 18 is connected to the bottom portion of a pneumatic hydraulic cylinder 5 integrated in one piece with the hydraulic cylinder 12 through a chuck cylinder 73. Inserted into the pneumatic hydraulic cylinder 5 is a pneumatic-hydraulic piston 13 dividing the inner portion of the cylinder 5 into an upper air chamber 5b and a lower hydraulic oil chamber 5a, and a cylindrical body 13a is integrally shaped in one piece with the under portion of the pneumatic hydraulic piston 13 and the air chamber 5b connected to an air chamber 72 shaped at the rear end of the valve chamber 44 of the drive section B through the air pipe 71, and the oil chamber 5a is connected to the oil chamber 12a of the hydraulic oil cylinder 12.
In the chuck cylinder 73, a hollow chuck piston 75 having a cylindrical body 74 is inserted. In the cylindrical body 13a of the pneumatic hydraulic piston 13, a coil spring 76a is inserted, and a rod 76 energized downwardly by the coil spring 76a is retractably extruded from a bottom wall of the cylindrical body 13a. On the lower tip of the rod 76, a hollow jaw case 77 moving slidably in the cylindrical body 74 of the chuck piston 75 is installed.
The lower inner surface of the jaw case 77 is shaped as a tapered circular surface 78 converging downwardly. A pair of jaws 14 are slidably inserted in the surface 78. Each of the jaws 14 is downwardly and outwardly energized by a spring 79 inserted in said jaw case 77 through a jaw pusher 80 having a V-shaped tip. Further, the bottom end of the cylindrical body 74 is closed except the hole for allowing passage of the core stem of the blind rivet, and each tip of said jaw case 77 and the jaws 14 contact with the bottom wall 74a of the body 74 in the state shown in FIG. 14 and FIG. 17.
The air chamber 81 positioned under the chuck piston 75 inserted in the chuck cylinder 73 is connected to the air port 82 located on the front end of the air cylinder 1 of the drive section B through an air supply pipe 83. Also, as shown in FIG. 22, in the bottom inner portion of the rivet nose 18, a pair of nose pieces 19 are pivotally supported and biased inwardly by a pair of springs 29 mounted on a pair of set screws 51.
Furthermore, in FIG. 22, numeral 53 identifies a pair of rivet passing holes for the blind rivet 33, and numeral 100 identifies the blind rivet holding belt described as follows.
The blind rivet holding belt 100 is shaped as a channeled section made of polypropylene, and has a plurality of feed holes 105d and upper and bottom tabs at every specified distance.
The rivet supply section C is composed of a rivet feed air cylinder 58 integrally installed on the side surface of the rivet nose 18, and a guide plate 59, as shown in FIG. 19 to FIG. 22. In FIG. 20, a piston 22 forwardly biased by a spring 31, is inserted in the rivet feed air cylinder 58, and in the piston 22, a shaft 23 having a feed pawl 23a is inserted and fixed by a screw 23b for preventing said shaft 23 from falling out. Furthermore, as shown in FIG. 17 the rivet feed air cylinder 58 is connected to the port 81a located on the upper portion of the chuck cylinder 73 through an air pipe 84.
Also in FIG. 19 and FIG. 20, numeral 58a identifies an air port connected to the air pipe 84.
The guide plate 59 has a pair of extrusions 60, 60 located upper and lower edges of the guide plate 59 for guiding the blind rivet-holding belt 100, a long hole 61 shown in FIG. 14, FIG. 16, FIG. 17, FIG. 20 and FIG. 21 for guiding the feed pawl 23a, and a nail 59a for preventing reverse motion of the blind rivet holding belt 100 protruding therefrom. Further, numeral 20 in FIG. 22 is a blind rivet-holding belt-pressing plate, and installed in the rivet nose 18 through a pair of pistons 21 and a pair of biasing springs 30, 30 for elastically pushing the blind rivet holding belt 100 against the guide plate 59. Also, a covering plate 30a fixed on the rivet nose 18 by screw threads (not shown) presses the springs 30 toward the pistons 21. Furthermore, numeral 34 shown in FIG. 14, FIG. 16, and FIG. 18 is a magazine for containing the blind rivet holding belt 100.
This rivet-containing magazine 34 is shaped in cylindrical form having a vertical axis against the longitudinal direction of the guide plate 59, then the blind rivet-holding belt 100 is wound spirally along said inner cylindrical wall, and is fed out along the guide plate 59.
The working of this improved continuous riveting machine constructed as described above in detail, is next described as follows.
The blind rivet-holding belt 100 is usually contained in the magazine 34, and before riveting, this riveting machine is in the state shown in FIG. 14. Namely, the operating lever 9 is released, and the blind rivet 33 is extruded downwardly from the bottom of the opened nose pieces 19.
In this condition, after the air supply port 50 (shown in FIG. 14) is connected to the pressurized air supply source (not shown), the main body of the blind rivet 33 is put in the hole of the steel sheets 63 to be riveted as shown in FIG. 14. Then by gripping the operating lever 9, the valve shaft 6 and the valve 8 go back, as the valve cam 10 rotates counterclockwise through the connecting rod 11 as shown in FIG. 18. As pressurized air is introduced into the air cylinder 1 through the connecting hole 43, the piston 2 advances, the hydraulic oil in the oil chamber 12a is supplied in the oil chamber 5a, and the pneumatic hydraulic piston 13 is raised to the top dead position as shown in FIG. 16.
Accordingly, the rod 76 and the jaw case 77 are raised upwardly. In this state, as a pair of jaws 14 are being biased downwardly by the spring 79 through the jaw pusher 80, the jaws 14 are slidably and downwardly extruded along the tapered surface 78 shaped on the jaw case 77 and go up while gripping the core stem 33a of the blind rivet 33. By pulling up the core stem 33a, the riveting action of the blind rivet 33 is performed. The core stem 33a is then torn from the blind rivet 33 at the position equivalent to the tip position of the nose piece 19.
As shown in FIG. 18, when the piston 2 reaches the stroke end, the pressurized air in the air cylinder 1 is supplied to the air chamber 81 from the air port 82 through the air pipe 83 shown in FIG. 17.
Accordingly, as also shown in FIG. 17, while the chuck piston 75 and the cylindrical body 74 rise up, at first a liner 74a in the body 74 contacts the tips of the jaws 14 and pushes up the jaws 14, then contacts the tip of the jaw case 77, and the jaws are accordingly opened.
Then, the cylindrical body 74 further rises from that position and the jaw case 77 also rises while compressing the bias spring 76a, and reaches the condition shown in FIG. 17.
When the chuck piston 75 reaches the top dead position, the pressurized air filled in the chuck cylinder 73 through the air pipe 83 is supplied to the rivet feed air cylinder 58 through the port 81a, the air pipe 83 and the port 58a. As shown in FIG. 20, the piston 22 then moves in the direction indicated by arrow, the feed pawl 23a installed on the tip of the shaft 23 moves along the long hole 61, and then the feed pawl 23a engaged with the feed hole 105 of the blind-rivet holding belt 100 transfers the holder 100 as much as one pitch, and sets the tip of the blind rivet 33 in the specified position in the rivet nose 18. (See FIG. 17).
Next, by releasing the operation lever 9, as shown in FIG. 15, owing to the clockwise rotation of the valve cam 10, the valve 8 is closed by the biasing force of the spring 25, the pressurized air is supplied into the air chamber 5b of the pneumatic-hydraulic cylinder 5 through the air chamber 72, the air pipe 71, as shown in FIG. 14, then the rod 76, the jaw case 77, the pneumatic-hydraulic piston 13, the chuck piston 75 and the cylindrical body 74 are pushed downwardly to the lower limit positions. In this case, as shown in FIG. 14, as the upper portion of the core stem 33a of the blind rivet 33 is inserted between a pair of jaws 14, 14, and contacts the bottom end of the jaw pusher 80, the blind rivet 33 is pushed downwardly. And after opening a pair of the nose pieces 19, the rivet 33 stops in the position of being extruded from the nose piece 19.
Furthermore, in this condition, as the pressurized air supply to the air cylinder 58 is exchanged and air pressure in the cylinder 58 is exhausted, the piston 22 of the rivet feed air cylinder simultaneously moves towards the left side as shown in FIG. 20 (in FIG. 14, moves towards the right). However, the blind rivet-holding belt 100 is prevented from reverse motion by the nail 59a, and only the feed pawl 23a disengaged from the feed hole 105 of the blind rivet-holding belt 100 moves backwardly as much as one pitch as said holder 100 remains at the present position, and again engages with the feed hole 105d positioned backwardly as much as one pitch.
According to the above description, one blind rivet 33 is riveted, and by repeating the aforementioned operation, it is possible to perform continuous riveting.
Also, as shown in FIG. 14, FIG. 16 and FIG. 17, the torn core stem 33a is continuously discharged while being inserted in the through hole of the holder 100 through the pass hole 53 shown in FIG. 22.
If the blind rivet-holding belts 100 in the containing magazine 34 are consumed, or if using the riveting machine originally charged with the holder 100 therein, the blind rivet 33 first placed on the head position of the rivet-holding belt 100 is placed on the position shown in FIG. 23, then by gripping the operating lever 9, raising the pneumatic hydraulic piston 13 and the chuck piston 75 simultaneously the blind rivet 33 is fed into the specified position.
In this case, the bottom end of the cylindrical body 74 and the blind rivet 33 are located in the positions shown in FIG. 13.
Next, by releasing the operating lever 9, the pneumatic-hydraulic piston 13 and the chuck piston 75 are pushed downwardly, the blind rivet 33 opens a pair of the nose pieces 19, 19 and extrudes from the bottom surface of these pieces 19, and all riveting preparations are finished.
The preceding actions are performed according to the above-described process. However, in this continuous riveting machine described above there existed the following drawbacks.
The length of the core stem 33a of the blind rivet 33 applicable to this riveting machine is longer than that of the standard blind rivet provided on the market.
As the torn core stems 33a are discharged together with the rivet holding-belt 100 while being kept between the tabs of the holding belt, there are drawbacks such as injury to the operator's hands, extrusion from the dust bag and bulkiness. Furthermore, it is cumbersome to separate the torn core stems made of metal and the holding belt made of plastics such as polypropylene when disposing of them.
The present invention was developed in consideration of the above-mentioned drawbacks, and its object is to provide a continuous riveting machine able to use standard blind rivets provided on the market and to continuously recover the torn core rivet stem of the blind rivets in the core-stem-storing case installed in the main body of the riveting machine.